Methods and systems for manufacturing fiber-reinforced resin parts are disclosed herein. In one embodiment, a method for manufacturing a fiber-reinforced resin part includes positioning a plurality of fibers on a mold surface of a female tool, and covering the fibers with a sealing layer. The method further includes pressing a portion of the covered fibers against an interior transition region (e.g., an internal radius) of the mold surface. While the portion of covered fibers is pressed against the interior transition region, air is removed from between the sealing layer and the mold surface to draw at least a partial vacuum between the sealing layer and the mold surface.
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12. A method for manufacturing a fiber-reinforced resin part, the method comprising:
positioning a plurality of fibers on a mold surface of a female tool, the mold surface including a first side region, a second side region, and an interior transition region positioned between the first and second side regions;
covering the fibers with a sealing layer;
compressing a first portion of the fibers against the first side region of the mold surface with a first portion of a tooling aid without compressing a second portion of the fibers against the second side region of the mold surface;
while compressing the first portion of fibers against the first side region of the mold surface, inflating an expandable member between a second portion of the tooling aid and the sealing layer to compress a third portion of the fibers between the expandable member and the interior transition region of the mold surface without compressing the second portion of fibers against the second side region of the mold surface;
allowing the uncompressed second portion of fibers on the second side region to move toward the interior transition region as the third portion of fibers is compressed between the expandable member and the interior transition region; and
while the expandable member is inflated, removing air from between the sealing layer and the mold surface to at least partially draw a vacuum between the sealing layer and the mold surface.
1. A method for manufacturing a fiber-reinforced resin part, the method comprising:
positioning a plurality of fibers on a mold surface of a tool, the mold surface including a first side region, a second side region, and an interior transition region positioned between the first and second side regions;
covering the fibers with a sealing layer;
pressing a first portion of the covered fibers against the first side region of the mold surface with a tooling aid without pressing a second portion of the covered fibers against the second side region of the mold surface;
while pressing the first portion of covered fibers against the first side region, pressing a third portion of the covered fibers against the interior transition region of the mold surface by inflating an expandable member operably coupled to the tooling aid against the sealing layer to compress the third portion of covered fibers between the expandable member and the interior transition region, without pressing the second portion of covered fibers against the second side region of the mold surface;
while pressing the third portion of covered fibers against the interior transition region of the mold surface with the pressing device, allowing the second portion of covered fibers on the second side region to move toward the interior transition region; and
removing air from between the sealing layer and the mold surface to draw at least a partial vacuum between the sealing layer and the mold surface.
18. A method for manufacturing a fiber-reinforced resin part, the method comprising:
positioning a plurality of fibers on a mold surface of a tool, the mold surface including a first, second, and third side regions and first and second interior transition regions, wherein the first interior transition region is positioned between the first and second side regions, and the second interior transition region is positioned between the first and third side regions;
covering the fibers with a sealing layer;
pressing a first portion of the covered fibers against the first side region of the mold surface with a tooling aid;
while pressing the first portion of covered fibers against the first side region, moving a first pressing device toward the first interior transition region of the mold surface by inflating a first expandable member against the sealing layer and pressing a second portion of the covered fibers against the first interior transition region without pressing a third portion of the covered fibers against the second side region of the mold surface;
while pressing the first portion of covered fibers against the first side region, moving a second pressing device toward the second transition region of the mold surface by inflating a second expandable member against the sealing layer and pressing a fourth portion of the covered fibers against the second interior transition region without pressing a fifth portion of the covered fibers against the third side region of the mold surface, wherein the first and second pressing devices are operably coupled to the tooling aid;
while pressing the first, second, and fourth portions of covered fibers, allowing the third portion of covered fibers on the second side region to move toward the first interior transition region, and allowing the fifth portion of covered fibers on the third side region to move toward the second interior transition region; and
removing air from between the sealing layer and the mold surface to draw at least a partial vacuum between the sealing layer and the mold surface.
2. The method of
3. The method of
4. The method of
5. The method of
6. The method of
7. The method of
8. The method of
9. The method of
moving the pressing device away from the third portion of covered fibers after drawing at least a partial vacuum between the sealing layer and the mold surface; and
after moving the pressing device away from the third portion of covered fibers, flowing resin between the sealing layer and the mold surface to infuse the plurality of fibers with resin.
10. The method of
11. The method of
pressing a fourth portion of the covered fibers against a second interior transition region of the mold surface spaced apart from the first interior transition region while pressing the third portion of the covered fibers against the first interior transition region, wherein the fourth portion of covered fibers are pressed against the second interior transition region of the mold surface without pressing a fifth portion of the covered fibers against a third side region of the mold surface positioned opposite to the second side region of the mold surface; and
while pressing the fourth portion of covered fibers against the second interior transition region of the mold surface, allowing the fifth portion of covered fibers on the third side region of the mold surface to move toward the second interior transition region.
13. The method of
14. The method of
15. The method of
16. The method of
17. The method of
inflating a second expandable member supported by the tooling aid against the sealing layer to compress a fourth portion of the fibers between the second expandable member and a second interior transition region of the mold surface spaced apart from the first interior transition region, wherein the fourth portion of covered fibers are pressed against the second interior transition region of the mold surface without pressing a fifth portion of the covered fibers against a third side region of the mold surface positioned opposite to the second side region of the mold surface; and
while pressing the fourth portion of covered fibers against the second interior transition region of the mold surface, allowing the fifth portion of covered fibers on the third side region of the mold surface to move toward the second interior transition region.
19. The method of
20. The method of
21. The method of
22. The method of
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The following disclosure relates generally to composite part manufacturing and, more particularly, to tooling aids for manufacturing composite parts with female tools.
Fiber-reinforced resin materials, or “composite” materials as they are commonly known, have many applications in the aerospace, automotive, and marine fields because of their high strength-to-weight ratios, corrosion resistance, and other unique properties. Conventional composite materials typically include glass, carbon, or polyaramide fibers in woven and/or non-woven configurations. The fibers can be pre-impregnated with uncured resin to form fiber plies in a raw material stage. The fiber plies can be manufactured into parts by laminating them on a mold surface. Heat and pressure can be applied to the laminated plies to cure the resin and harden the laminate in the shape of the mold. The heat and pressure can be applied with an autoclave, a heated flat or contoured forming tool, or a combination of methods including the use of a vacuum bag.
Composite parts can be formed in the above manner on both male and female tools. With male tools, the fiber plies are applied to an exterior mold surface that forms an inner mold line of the part. Adding plies to the lay-up on a male tool increases the thickness of the part and changes the outer mold line, but the inner mold line remains unchanged. Conversely, with female tools, the fiber plies are applied to an interior mold surface that forms an outer mold line of the part. Adding plies to the lay-up on a female tool increases the thickness of the part and changes the inner mold line, but the outer mold line remains unchanged.
Female tools are desirable when the mating surface is located on the exterior of a part because female tools allow the outer mold line (i.e., the exterior surface) to be tightly controlled. Female tooling (also known as outer mold line tooling) is also desirable when making multiple parts having the same external dimensions but different thicknesses. Aircraft, for example, often include multiple fuselage frames having the same external dimensions but different thicknesses. In this situation, a single female tool can be used to make all of the frames, regardless of thickness, because the female tool allows the thickness to vary without changing the external dimensions. If future growth of the aircraft requires further thickening of the frames, this can be achieved without changing tooling. Conversely, if male tooling were used, then a separate tool would be required for each different frame thickness.
One problem that arises when manufacturing composite parts with female tooling is that the fiber plies tend to bridge across internal radii on the mold surface.
The present invention is directed generally toward methods and systems for manufacturing composite parts with female tools. A method for manufacturing a composite part in accordance with one aspect of the invention includes positioning a plurality of fibers on a mold surface of a tool, and covering the fibers with a sealing layer. The method can further include pressing a portion of the covered fibers against an interior transition region of the mold surface with a pressing device. While the portion of covered fibers is being pressed against the interior transition region, air can be removed from between the sealing layer and the mold surface to draw at least a partial vacuum between the sealing layer and the mold surface. In one embodiment, the portion of covered fibers can be pressed against the interior transition region of the mold surface by a pneumatic pressing device. In another embodiment, the portion of covered fibers can be pressed against the interior transition region by a mechanical pressing device.
A tooling system for manufacturing a composite part in accordance with another aspect of the invention includes a tool and a tooling aid configured to cooperate with the tool. The tool can have a mold surface with a first side region, a second side region, and an interior transition region positioned between the first and second side regions. The tooling aid can include an outwardly movable pressing device configured to compress a portion of fibers against the interior transition region of the mold surface when manufacturing a composite part with the tool. In one embodiment, the pressing device can include an inflatable member. In another embodiment, the pressing device can include a mechanical driver.
The following disclosure describes methods and systems for manufacturing composite parts. Certain details are set forth in the following description and in
Many of the details, dimensions, angles, and other features shown in the Figures are merely illustrative of particular embodiments of the invention. Accordingly, other embodiments can have other details, dimensions, angles, and features without departing from the spirit or scope of the present invention. In addition, further embodiments can be practiced without several of the details described below.
In the Figures, identical reference numbers identify identical or at least generally similar elements. To facilitate the discussion of any particular element, the most significant digit or digits of any reference number refer to the Figure in which that element is first introduced. For example, element 230 is first introduced and discussed with reference to
To manufacture a composite part with the tool 202, a fiber material 210 is positioned against the mold surface 204. A sealing layer 220 (e.g., a vacuum bag) can be positioned over the fiber material 210 for subsequent evacuation of the space between the sealing layer 220 and the mold surface 204. In one embodiment, the fiber material 210 can include a plurality of woven and/or non-woven fibers preimpregnated with resin. In another embodiment, the fiber material 210 can be applied to the mold surface 204 dry and infused with resin during or after the evacuation process. One method for infusing a dry fiber lay up with resin is described in detail in co-pending U.S. application Ser. No. 10/485,725, entitled “CONTROLLED ATMOSPHERIC PRESSURE RESIN INFUSION,” filed May 28, 2003 as PCT Application PCT/US03/16794, and incorporated herein in its entirety by reference.
The tooling aid 230 can include a support portion 232 extending downwardly from a base portion 231. The base portion 231 can be held against the tool 202 by an arrangement of clamping devices 242 to position the support portion 232 in the tool 202. As described in greater detail below, when the support portion 232 is fully positioned in tool 202, a holding device 238 (e.g., a pad) positioned on a distal end of the support portion 232 presses against the sealing layer 220 and traps a portion of the fiber material 210 against the second side region 205 of the mold surface 204. The holding device 238 can include a compressible material such as rubber, or other materials such as Teflon, plastic, etc. that can hold the fiber material 210 in position against the tool surface without damaging the sealing layer 220.
The tooling aid 230 further includes a first pressing device 234a and a second pressing device 234b positioned toward the distal end of the support portion 232. The pressing devices 234 are positioned to face outwardly toward the corresponding transition regions 206 of the tool 202 when the support portion 232 is fully positioned in the tool 202. Each of the pressing devices 234 of the illustrated embodiment includes an expandable member 236 (e.g., an inflatable bladder, tube, etc.) that expands outwardly against the corresponding transition region 206 when inflated, as described in more detail below with reference to
Referring next to
After the sealing layer 220 has been sufficiently evacuated, the expandable member 236 can be deflated as shown in
Use of the tooling aid 230 in the manner described above with reference to
In the illustrated embodiment, a fiber material 410 is positioned on a mold surface 404 of the tool 402, and a sealing layer 420 is positioned over the fiber material 410. The contoured former 437 is positioned against the sealing layer 420 in a transition region 406 of the mold surface 404. The contoured former 437 can include an outer forming surface 439 that at least approximates the shape of the transition region 406.
As shown in
Although the pressing devices 234 and 434 described above with reference to
Each of the mechanical pressing devices 534 includes at least one driving member 546 rotatably coupled to a contoured former 537. The contoured formers 537 can include rigid or semi-rigid tubular segments having cross-sectional radii that approximate the curvature of the corresponding transition regions 506 of the mold surface 504. In the illustrated embodiment, each of the driving members 546 includes a threaded portion 542 threadably engaging a corresponding threaded bore 533 extending through a base portion 531 of the tooling aid 530. The base portion 531 can be temporarily fixed to the tool 502 by clamps or other suitable devices. Each of the driving members 546 further includes a head portion 541 configured to be turned by a wrench or other torquing device.
Rotation of the driving members 546 in a first direction 561 moves the corresponding contoured formers 537 toward the adjacent transition regions 506. In this manner, the pressing devices 534 can be used to compress a fiber material 510 into the transition regions 506 while the space under a sealing layer 520 is at least partially evacuated as described above with reference to
In the illustrated embodiment, the interlocking feature 660 includes a male portion 662 extending from the first contoured former 537a, and a corresponding female portion 664 extending from the adjacent second contoured former 537b. The female portion 664 is configured to receive the male portion 662 in an overlapping manner to provide an at least approximately continuous contoured former 637. In this way, the interlocking tooling aids 530 can provide at least approximately continuous pressure over long and/or curved transition regions of a female tool.
In another aspect of this embodiment, the tool 702 is curved and relatively long. Such a tool can be used, for example, to manufacture composite frame sections for aircraft fuselages and/or other structures. When manufacturing such parts with the tooling system 700, pressure from the tooling aids 730 can be applied to the composite material (not shown) in at least one of two ways. The first method involves applying pressure with the tooling aid 730e near a mid-portion 773 of the tool 702 first, and then working outwardly from there toward a first end 771 and an opposite second end 772. The second method involves applying pressure with the tooling aid 730a near the first end 771 of the tool 702 first, and then working from there toward the second end 772. Applying pressure to the composite material using one of these two methods can avoid material bunching and/or wrinkles in the finished part. For composite parts having ply-ramps or joggles, the contoured formers 537 (
From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention. For example, aspects described in the context of particular embodiments can be combined or eliminated in other embodiments. Accordingly, the invention is not limited, except as by the appended claims.
Cundiff, Thomas R., Modin, Andrew E., Woods, Jack A., Brustad, Val G., Hanks, Dennis J.
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